Agricultural work vehicle

Abstract

The present invention relates to a technology for controlling transmission of an agricultural work vehicle. A transmission control method for an agricultural work vehicle according to the present invention has a first control section and a second control section having different rates of change of pressure (hereinafter referred to as pressing force) applied to disks of a multi-plate clutch during an engagement process of the multi-plate clutch. In the first control section, a proportional control valve is controlled such that the pressing force increases with an average rate of change smaller than a rate of change of displacement of an operation pedal, and in the second control section, the proportional control valve is controlled such that the rate of change of the pressing force is greater than that in the first control section. When the present invention is applied, impact that may occur during a transmission process can be reduced.

Description

agricultural work vehicles

[0001] The present invention relates to a technology for controlling the transmission of an agricultural work vehicle.

[0002] Agricultural work vehicles are work vehicles used for performing agricultural work, including agricultural tractors, rice transplanters, and combines.

[0003] Farm work performed by agricultural work vehicles usually involves driving agricultural work vehicles.

[0004] During agricultural work, driving agricultural work vehicles requires frequent shifting between forward and reverse.

[0005] To change gears in agricultural work vehicles, agricultural work vehicles are equipped with clutches.

[0006] The clutch is operated to cut or connect power during the shifting process.

[0007] The clutch needs to be disengaged to shift.

[0008] When shifting gears with the clutch disengaged, the clutch must be engaged.

[0009] When the clutch is engaged, power from the engine or drive motor (hereinafter referred to as the “power source”) can be transmitted to the wheels.

[0010] Recently, there is a trend toward installing electronic control technology in agricultural work vehicles.

[0011] A multi-disc clutch is a clutch suitable for electronic control technology.

[0012] The multi-plate clutch has a structure in which discs are arranged in the clutch housing and clutch hub, respectively.

[0013] The driving discs coupled to the clutch housing and the driven discs coupled to the clutch hub are arranged alternately with each other.

[0014] When the discs are separated from each other by the pressure spring, the multi-plate clutch is disengaged and gear switching becomes possible.

[0015] A multi-plate clutch is engaged when a pressure greater than the elastic force of the pressure spring is applied through the clutch pressure plate, causing the discs to come into contact with each other.

[0016] For the engagement operation of the multi-plate clutch, conventional agricultural work vehicles are equipped with an operation pedal, an operation sensor, and a hydraulic valve.

[0017] The control pedal is operated by the user.

[0018] A user can input an operation command for the multi-plate clutch into the controller by operating the operation pedal.

[0019] The user can operate the operating pedal by stepping on the operating pedal or by taking his / her foot off the operating pedal.

[0020] The operation sensor detects the operation status of the operation pedal and transmits the detected information to the controller.

[0021] When the user operates the operation pedal, the operation sensor transmits the detected information to the controller.

[0022] The hydraulic valve connects or blocks the hydraulic line from the hydraulic pump to the multi-plate clutch.

[0023] Depending on the operating status of the hydraulic valve, the multi-plate clutch is operated by supplying or removing hydraulic pressure to the multi-plate clutch.

[0024] Hydraulic pressure can be generated from a hydraulic pump and applied to a multi-plate clutch through a hydraulic valve.

[0025] When pressure is applied to the discs by hydraulic pressure provided by the hydraulic pump, the discs come into close contact with each other, thereby engaging the multi-plate clutch.

[0026] When the hydraulic pressure is removed, the multi-plate clutch is disengaged by the elastic force of the pressure springs causing the discs to separate from each other.

[0027] The controller can ultimately control the operation of the multi-plate clutch by controlling the hydraulic valve according to information received from the operation sensor.

[0028] According to conventional technology, when a user lifts his / her foot from the operating pedal, the discs are quickly and strongly pressed together in a short period of time by strong hydraulic pressure, causing a large shifting shock.

[0029] Because agricultural work involves frequent gear changes, shocks occur frequently. The noise and vibration caused by these frequent shocks quickly accumulate in the user's driving fatigue.

[0030] [Prior Art Literature]

[0031] [Patent Document]

[0032] (Patent Document 1) Republic of Korea Patent Publication No. 10-2024-0175936

[0033] It is necessary to reduce the noise and shock generated when engaging a multi-plate clutch during the gear shifting process of an agricultural work vehicle.

[0034] A transmission control method in an agricultural work vehicle according to a first aspect of the present invention comprises: an operation state confirmation step of confirming an operation state of an operation pedal for operating a multi-plate clutch; a proportional control valve control step of controlling a proportional control valve so that the multi-plate clutch is engaged when the operation state of transmitting power is confirmed in the operation state confirmation step; wherein the proportional control valve control step includes a first control section and a second control section in which the rates of change of pressure (hereinafter referred to as “pressure”) applied to disks of the multi-plate clutch are different from each other, and the second control section starts from a point where the first control section ends, and in the first control section, the proportional control valve is controlled so that the pressure increases at an average rate of change smaller than the rate of change of the displacement of the operation pedal, and in the second control section, the proportional control valve is controlled so that the rate of change of the pressure is larger than that in the first control section.

[0035] The above first control section is divided into a contact point entry section and a transmission rate increase section, and in the contact point entry section, the pressure enters the point where contact between the disks of the multi-plate clutch begins (SP, hereinafter referred to as the “contact start point”), and in the transmission rate increase section, the power transmission rate increases from the point where the contact point entry section ends, and the proportional control valve is controlled so that the rate of change of the pressure is different in the contact point entry section and the transmission rate increase section.

[0036] The proportional control valve is controlled so that the rate of change in the pressure in the above-mentioned transmission rate increase section is smaller than the rate of change in the pressure in the above-mentioned contact point entry section.

[0037] The proportional control valve is controlled so that the pressure increases discontinuously in the above contact point entry section.

[0038] The proportional control valve is controlled so that the pressure in the above contact point entry section increases in a stepwise manner.

[0039] In the above transmission rate increase section, the proportional control valve is controlled so that the power transmission rate by the multi-plate clutch reaches 100%, and in the second control section, the proportional control valve is controlled so that the pressure reaches the maximum.

[0040] The initial starting pressure can be arbitrarily set at the above contact point entry section.

[0041] The time required for the entry section of the above contact point is adjusted based on the acceleration information received from the acceleration sensor.

[0042] If the operation state confirmed in the above operation state confirmation step is not the maximum value, the proportional control valve is controlled in the second control section to maintain the pressure lower than the maximum pressure for a predetermined period of time.

[0043] A transmission control method in an agricultural work vehicle according to a second aspect of the present invention comprises: an operation state confirmation step for confirming an operation state of an operation pedal for operating a multi-plate clutch; a proportional valve control step for controlling a proportional control valve so that the multi-plate clutch is engaged when the operation state for transmitting power is confirmed in the operation state confirmation step; and the proportional valve control step controls the proportional control valve so that a pressure less than the maximum pressure is applied to the discs of the multi-plate clutch from a point where power transmission begins to occur to a point where the power transmission rate becomes 100%.

[0044] The proportional control valve is controlled so that the pressure applied to the disks is maintained within a predetermined range from the point where power transmission begins to the point where power transmission reaches 100%.

[0045] An agricultural work vehicle according to the present invention comprises: a multi-plate clutch capable of transmitting or blocking power; a proportional control valve for operating the multi-plate clutch to enable the multi-plate clutch to transmit or block power; a controller capable of controlling the operating state of the multi-plate clutch by controlling the proportional control valve; an operating pedal for inputting a user's command to the controller; and a displacement sensor for detecting a displacement of the operating pedal; wherein the controller executes a shift according to the above-described shift control method based on detection information from the displacement sensor.

[0046] According to the agricultural work vehicle of the present invention, the following effects are achieved during the gear shifting process.

[0047] First, even if the user operates the operating pedal rapidly, the pressure applied to the discs increases relatively slowly, preventing excessive shock that may occur momentarily.

[0048] Second, since the initial pressure can be set arbitrarily, the phenomenon of delayed response of the multi-plate clutch can be minimized depending on the manager's choice.

[0049] Third, since the engagement strength of the multi-plate clutch can be controlled for a given period of time, various operations of the multi-plate clutch are possible according to the manager's choice, thereby expanding the range of operations for agricultural work vehicles.

[0050] Ultimately, the driving comfort is improved and the user's satisfaction with the agricultural work vehicle is enhanced by being able to operate the gears according to the intended operation.

[0051] Figure 1 is a schematic diagram of the main components of an agricultural work vehicle according to a first embodiment of the present invention.

[0052] Figures 2 to 4 are graphs for explaining the control of a multi-plate clutch performed in the agricultural work vehicle of Figure 1.

[0053] Figure 5 is a flowchart for explaining a gear control method according to the present invention.

[0054] Figure 6 is a schematic diagram of the main components of an agricultural work vehicle according to a second embodiment of the present invention.

[0055] Figure 7 is a graph for explaining the agricultural work vehicle of Figure 6.

[0056] Figure 8 is a graph for explaining an agricultural work vehicle according to a third embodiment of the present invention.

[0057] Figure 9 is a schematic diagram of the main components of an agricultural work vehicle according to a third embodiment of the present invention.

[0058] Preferred embodiments according to the present invention are described with reference to the attached drawings, but for the sake of brevity, descriptions of well-known components are omitted or compressed as much as possible.

[0059] <First Embodiment>

[0060] FIG. 1 is a schematic diagram for explaining the main components of an agricultural work vehicle (100, hereinafter referred to as “work vehicle”) according to a first embodiment of the present invention.

[0061] The work vehicle (100) of Fig. 1 includes a multi-plate clutch (110), an operator (120), a controller (130), an operating pedal (140), and a displacement sensor (150).

[0062] The multi-plate clutch (110) has a structure in which discs are arranged in the clutch housing and clutch hub, respectively.

[0063] The clutch housing is coupled to the drive shaft of the power generation source and rotates together with the drive shaft.

[0064] The clutch housing has drive discs mounted on its inner side.

[0065] The clutch hub is connected to the driven shaft, which transmits driving power to the wheels, and rotates together with the driven shaft.

[0066] The clutch hub has passive discs attached to its outer surface.

[0067] The driving disks and the driven disks are arranged alternately.

[0068] When the discs are separated from each other by the pressure spring, the multi-plate clutch is disengaged.

[0069] When the multi-plate clutch (110) is disassembled, the drive shaft and the driven shaft are separated by the mutually spaced disks, so that the agricultural work vehicle (100) can change gears.

[0070] When pressure (hereinafter referred to as “pressure”) is applied to the discs of the multi-plate clutch (110) by the clutch pressure plate, the discs come into contact with each other and are pressed against each other.

[0071] The pressure exerts a force on the discs greater than the elastic force of the pressure spring.

[0072] When the disks are in close contact with each other, the multi-plate clutch (110) is in a locked state.

[0073] When the multi-plate clutch (110) is engaged, the drive shaft and the driven shaft are connected by mutually close discs.

[0074] The combined drive shaft and driven shaft rotate together, transmitting power generated from the power generation source to the wheels.

[0075] The actuator (120) operates the multi-plate clutch (110).

[0076] The actuator (120) includes a hydraulic valve that operates the multi-plate clutch (110) by transmitting or blocking the hydraulic pressure of the hydraulic pump (OP) to the multi-plate clutch (110).

[0077] When the actuator (120) transmits hydraulic pressure to the multi-plate clutch (110), the clutch pressure plate applies pressure to the discs, causing the discs to come into close contact with each other.

[0078] When the actuator (120) blocks the hydraulic pressure, the disks are separated from each other by the elastic force of the pressure spring.

[0079] According to a preferred example of the present invention, it is preferable that the hydraulic valve be provided as a proportional control valve (121) capable of controlling hydraulic pressure.

[0080] The actuator (120) can control the hydraulic pressure provided to the multi-plate clutch (110) by including a proportional control valve (120).

[0081] The proportional control valve (121) operates to supply or block the hydraulic pressure of the hydraulic pump (OP) to or from the multi-plate clutch (110).

[0082] The proportional control valve (121) can also provide hydraulic pressure regulated at an arbitrary level to the multi-plate clutch (110).

[0083] The controller (130) can control the operating state of the multi-plate clutch (110) by controlling the actuator (120).

[0084] The controller (130) can control the operating state of the multi-plate clutch (110) by controlling the proportional control valve (121).

[0085] The controller (130) can control the engagement strength of the multi-plate clutch (100) by controlling the proportional control valve (121).

[0086] In the case of transmitting power, the controller (130) performs control to engage the multi-plate clutch (110) so that the multi-plate clutch (110) can transmit power.

[0087] In the case of power cut-off, the controller (130) performs control to disengage the multi-plate clutch (100) so that the multi-plate clutch (110) can cut off the power.

[0088] The controller (130) controls the proportional control valve (121) differently when transmitting power and when blocking power.

[0089] During the dismantling process of the multi-plate clutch (110), the controller (130) controls the proportional control valve (121) so that the actuator (120) provides hydraulic pressure in proportion to the displacement of the operating pedal (140).

[0090] The controller (130) divides the engagement process of the multi-plate clutch (110) into multiple control sections and controls the actuator (120) differently for each of the multiple control sections.

[0091] The controller (130) controls the proportional control valve (121) differently for each of the multiple control sections during the engagement process of the multi-plate clutch (110).

[0092] Control by multiple control sections will be described later.

[0093] The operating pedal (140) is provided to input the user's commands.

[0094] The operating pedal (140) is provided to be displaced while performing a swing movement.

[0095] The user can displace the operating pedal (140) by stepping on the operating pedal (140) with his / her foot or by taking his / her foot off the operating pedal (140).

[0096] The user's command is input by displacing the operating pedal (140).

[0097] The user's action of stepping on the operating pedal (140) corresponds to the input of a command to disengage the multi-plate clutch (110).

[0098] The user's action of taking his / her foot off the operating pedal (110) corresponds to the input of a command to engage the multi-plate clutch (110).

[0099] When the user takes his / her foot off the operating pedal (110), the operating pedal (110) returns to its original position before the user stepped on it by the return spring.

[0100] When the user suddenly lifts his / her foot off the operating pedal (110), the operating pedal (110) is quickly returned to its original position by the elastic force of the return spring.

[0101] When the user wants to perform forward and reverse gear shifting, etc., he / she steps on the operating pedal (140) to disengage the multi-plate clutch (110) and then operates the shift lever.

[0102] When the user completes the operation of the shift lever, the user removes his / her foot from the operation pedal (140) to engage the multi-plate clutch (110).

[0103] The displacement sensor (150) detects the swing movement of the operating pedal (140).

[0104] The detection information detected by the displacement sensor (150) includes the displacement and displacement direction of the operating pedal (140).

[0105] The displacement sensor (150) detects the displacement of the operating pedal (140) that performs a swing motion.

[0106] The displacement sensor (150) detects the displacement direction of the swinging operation pedal (140).

[0107] The displacement sensor (150) may be equipped with a potentiometer.

[0108] The detection information detected by the displacement sensor (150) is transmitted to the controller (130).

[0109] The controller (130) can know the displacement and displacement direction of the operating pedal (140) from the detection information received from the displacement sensor (150).

[0110] The controller (130) has a matching table regarding the displacement of the operating pedal (140) and the hydraulic pressure provided by the operating device (120).

[0111] The controller (130) can use the matching table to determine the hydraulic pressure to be provided to the multi-plate clutch (110) in response to the displacement of the operating pedal (140).

[0112] The controller (130) can determine whether to control to transmit power or to block power based on information about the direction of displacement.

[0113] When the controller (130) determines whether power should be transmitted or power should be cut off, it controls the proportional control valve (121) according to the determination.

[0114] In cases where power must be transmitted, the controller (130) performs control to engage the multi-plate clutch (110), and in cases where power must be cut off, the controller (130) performs control to disengage the multi-plate clutch (110).

[0115] In particular, when power must be transmitted, the controller (130) divides the control section into multiple control sections and controls the actuator (120) differently for each of the multiple control sections.

[0116] The proportional control valve (121) is controlled by the controller (130) to provide different hydraulic pressures for each of the multiple control sections.

[0117] Below, the control of the multi-plate clutch (110) performed in the above work vehicle (100) is explained in each case.

[0118] 1. When stepping on the operating pedal (140) [On-going]

[0119] When a shift is required, the user steps on the operating pedal (140).

[0120] When the operating pedal (140) is stepped on, the controller (130) controls the multi-plate clutch (110) to cut off power.

[0121] The controller (130) controls the proportional control valve (121) to reduce the hydraulic pressure provided to the multi-plate clutch (110) in response to the displacement of the operating pedal (140) based on the detection information from the displacement sensor (150).

[0122] The controller (130) controls the proportional control valve (121) to generate hydraulic pressure corresponding to each of the displaced positions of the operating pedal (140) according to the matching table.

[0123] The pressure applied to the discs of the multi-plate clutch (110) by the hydraulic pressure of the hydraulic pump (OP) can be reduced from maximum to 0 in proportion to the displacement of the operating pedal (140).

[0124] When the pressure applied to the discs by the clutch pressure plate becomes 0, the multi-plate clutch (110) is disengaged by the elastic force of the pressure spring, and gear shifting becomes possible.

[0125] When the multi-plate clutch (110) is disengaged, the user can operate the forward / reverse shift lever or the drive shift lever (hereinafter collectively referred to as the “shift lever”).

[0126] 2. When taking your foot off the operating pedal (140) [Off-going]

[0127] When the operation of the shift lever is completed, the user takes his / her foot off the operation pedal (140).

[0128] When the foot is lifted from the operating pedal (140), the controller (130) controls the multi-plate clutch (110) to transmit power.

[0129] The controller (130) controls the proportional control valve (121) to increase the hydraulic pressure provided to the multi-plate clutch (110) according to the detection information received from the displacement sensor (150).

[0130] The pressure acting on the discs of the multi-plate clutch (110) increases from 0 to maximum.

[0131] The user can either abruptly remove his / her foot from the operating pedal (140) or gradually remove his / her foot while reducing the force applied to the pedal.

[0132] When the user abruptly removes his / her foot from the operating pedal (140), the operating pedal (140) is rapidly operated by the return spring, so the controller (130) determines that it is in a state of rapid return.

[0133] In a rapid return state, the controller (130) performs control on the proportional control valve (121) in response to the rapid return state.

[0134] When the user relatively slowly removes his / her foot from the operating pedal (140) in preparation for a rapid return state, the operating pedal (140) is slowly operated, so the controller (130) determines that it is a normal return state.

[0135] In a normal return state, the controller (130) performs control on the proportional control valve (121) in response to the normal return state.

[0136] In the case of transmitting power, the controller (130) divides it into multiple control sections and controls the proportional control valve (121) differently for each of the multiple control sections.

[0137] The plurality of control sections includes a first control section and a second control section.

[0138] The second control section begins where the first control section ends.

[0139] The first and second control sections have different rates of change in pressure.

[0140] In the first control section, the power transmission rate through the multi-plate clutch (110) increases.

[0141] In the first control section, the pressure is increased with an average change rate lower than the displacement change rate of the operating pedal (140).

[0142] In the first control section, the controller (130) controls the proportional control valve (121) so that the pressure increases with an average change rate lower than the displacement change rate of the operating pedal (140).

[0143] The first control section is divided into a contact point entry section and a transmission rate increase section.

[0144] At the contact point entry section, the pressure is applied to the point where contact begins between the discs of the multi-plate clutch.

[0145] The transmission rate increase section starts from the point where the contact point entry section ends.

[0146] In the transmission rate increasing section, the power transmission rate of the multi-plate clutch (110) increases as the contact between the disks increases.

[0147] In the transmission rate increase section, the power transmission rate of the multi-plate clutch (110) increases to 100%.

[0148] According to the present invention, the rate of change of the pressure is different in the contact point entry section and the transmission rate increase section.

[0149] The controller (130) controls the proportional control valve (121) so that the rate of change in the pressure in the transmission rate increase section is smaller than the rate of change in the pressure in the contact point entry section.

[0150] The second control section begins at the point where the transmission rate increase section ends.

[0151] In the second control section, the engagement strength of the multi-plate clutch (110) can be increased to the maximum.

[0152] In the second control section, the rate of change in pressure is greater than in the first control section.

[0153] Since the power transmission ratio reaches 100% in the first control section, the pressing force increases rapidly and the fastening strength of the multi-plate clutch (110) reaches its maximum.

[0154] The controller (130) controls the proportional control valve (121) so that the pressure change rate of the second control section is greater than the pressure change rate of the first control section.

[0155] Next, examples of control performed during the engagement process of the multi-plate clutch (110) will be explained by dividing them into the operating states of the operating pedal (140).

[0156] (1) Rapid operating condition

[0157] The graph in Fig. 2 shows control according to the rapid operating state.

[0158] A sudden operation state occurs when the user suddenly removes his foot from the operation pedal (140).

[0159] Judgment as to whether or not a state of rapid manipulation exists can be made based on preset criteria.

[0160] The preset criteria may be the speed or time at which the operating pedal (140) returns.

[0161] The controller (130) controls the proportional control valve (121) to gradually increase the hydraulic pressure to the point (SP, hereinafter referred to as the “contact start point”) where the discs in the multi-plate clutch (110) begin to contact each other when the operating pedal (140) is rapidly operated.

[0162] As the hydraulic pressure increases, the pressurization force increases.

[0163] The point from which the pressure increase begins to the contact start point (SP) is the contact point entry section (ES).

[0164] As in the example of Fig. 2, the pressure up to the contact start point (SP) increases in a discontinuous stepwise manner.

[0165] The controller (130) controls the proportional control valve (121) so that the actuator (120) gradually increases the hydraulic pressure at the contact point entry section (ES).

[0166] Since a proportional control valve (121) capable of controlling hydraulic pressure is applied, the pressure applied to the discs in the multi-plate clutch (110) can be increased stepwise.

[0167] It is desirable that the average rate of change (average slope) of the pressure at the contact point entry section (ES) be smaller than the rate of change in displacement of the operating pedal (140).

[0168] The matching table is not used in the contact point entry section (ES).

[0169] The multi-plate clutch (110) begins transmitting power from the contact start point (SP).

[0170] According to the first embodiment, the point in time at which the discs of the multi-plate clutch (110) come into contact is delayed by having a contact point entry section (ES).

[0171] The controller (130) intentionally delays the point of contact between the disks by controlling the proportional control valve (121) according to the contact point entry section (ES).

[0172] When the pressure reaches the contact start point (SP), the contact point entry section (ES) ends.

[0173] The transmission rate increase section (GS) begins from the contact start point (SP), where the contact point entry section (ES) ends.

[0174] In the transmission rate increase section (GS), the power transmission rate through the multi-plate clutch (110) increases to 100%.

[0175] In the transmission rate increase section (GS), the controller (130) controls the proportional control valve (120) so that the pressure can be maintained within a certain range.

[0176] The ideal situation is for the pressure to remain horizontal throughout the transmission rate increasing section (GS).

[0177] The controller (130) controls the proportional control valve (130) in the transmission rate increase section (GS) based on an ideal situation in which the pressure is maintained in the same horizontal state.

[0178] The average rate of change of the pressure in the transmission rate increasing section (GS) is smaller than the average rate of change of the pressure in the contact point entry section (ES).

[0179] Depending on the usage environment of agricultural work vehicles, the actual pressure may fluctuate somewhat in the transmission rate increase section (GS).

[0180] The pressure in the transmission rate increasing section (GS) is maintained within a certain range that is less than the maximum pressure that can be applied to the discs. Accordingly, the speed at which the power transmission rate of the multi-plate clutch (110) increases is slowed down and the acceleration shock is reduced.

[0181] In the transmission force increase section (GS), the pressing force remains the same within a certain range, but the bonding strength gradually increases.

[0182] The matching table is not used even in the transmission power increase section (GS).

[0183] In the transmission power increase section (GS), the power transmission ratio of the multi-plate clutch (110) increases from 0% to 100%.

[0184] The contact point entry section (ES) and the transmission increase section (GS) are within the first control section (CS1).

[0185] When the first control section (CS1) ends, the second control section (CS2) begins.

[0186] When the transmission rate increase section (GS) ends, the second control section (CS2) begins.

[0187] In the second control section (CS2), the fastening strength of the multi-plate clutch (110) is strengthened.

[0188] In the second control section (CS2), the pressure increases linearly with a constant slope.

[0189] In the second control section (CS2), the pressure increases as quickly as the displacement change rate of the operating pedal (140).

[0190] In the second control section (CS2), the controller (130) controls the proportional control valve (121) so that the pressure increases rapidly.

[0191] When the pressing force is rapidly increased in the second control section (CS2) to maximize the fastening strength, unintended disassembly of the multi-plate clutch (110) due to any impact is prevented.

[0192] The controller (130) controls the proportional control valve (121) so that the rate of change in the pressure in the second control section (CS2) is greater than the rate of change in the pressure in the first control section (CS1).

[0193] Mechanical friction shock and acceleration shock occurring during the gear shifting process primarily occur until the end of the transmission rate increase section (GS). Therefore, the pressure can be increased more rapidly in the second control section (CS2) than in the first control section (CS1).

[0194] The pressurized force increases in a discontinuous step-like manner in the contact point entry section (ES), is maintained within a certain range in the transmission rate increase section (GS), and then increases linearly with a relatively large slope to a maximum from the point where the transmission rate increase section (GS) ends when the power transmission rate becomes 100%.

[0195] In the second control section, the controller (130) can be implemented to control the operation of the multi-plate clutch (110) with a pressure corresponding to each displacement position of the operating pedal (140) according to the matching table.

[0196] In general, the shock generated during the engagement process of a multi-plate clutch (110) is caused by the momentary excessive mechanical contact and rapid acceleration of the discs.

[0197] When the present invention is applied, the pressure gradually increases slowly until the power transmission ratio of the multi-plate clutch (110) reaches 100%, thereby reducing shock during the gear shifting process.

[0198] Since the pressure is gradually increased in a step-like manner up to the contact starting point (SP), momentary excessive contact and impact of the disks at the contact starting point (SP) are prevented.

[0199] In the transmission rate increase section (GS), the controller (130) controls the proportional control valve (121) so that a pressure less than the maximum pressure is applied, so that the shock in the situation where the power transmission rate of the multi-plate clutch (110) increases is also reduced.

[0200] Once the entire section where impact can occur has passed, the controller (130) completes the shift by relatively quickly increasing the pressure.

[0201] (2) General operating conditions

[0202] The graph in Fig. 3 shows control in a general operating state.

[0203] The general operating state is one in which the user does not abruptly lift his / her foot from the operating pedal (140) but rather slowly lifts it.

[0204] Judgment as to whether or not a normal operating condition exists can also be made based on preset criteria.

[0205] The preset criteria may be the speed or time at which the operating pedal (140) returns to its original position.

[0206] The general operating condition is generally the same as the rapid operating condition.

[0207] In a normal operating state, the user operates the operating pedal (140) without completely removing his / her foot from the operating pedal (140), so the displacement of the operating pedal (140) increases irregularly and unstably, which is different from the rapid operating state.

[0208] Even in normal operating conditions, there is a first control section (CS1) and a second control section (CS2), and the first control section (CS1) is divided into a contact point entry section (ES) and a transmission power increase section (GS).

[0209] Despite the irregular position change of the operating pedal (140), in the first control section (CS1), the pressure increases and the power transmission rate increases in the same pattern as in the rapid operating state.

[0210] However, in normal operating conditions, the pressure and power transmission rate increase more gradually than in rapid operating conditions.

[0211] In normal operating conditions, the pressure can be maintained at an arbitrary value according to the user's choice.

[0212] The user can place the operating pedal (140) in the first position by fully depressing the operating pedal (140) with his / her foot, place the operating pedal (140) in the second position by completely removing his / her foot from the operating pedal (140), or maintain the operating pedal (140) in any one of a number of arbitrary positions (hereinafter referred to as “third positions”) between the first and second positions.

[0213] When the operating pedal (140) is positioned in the first position, the multi-plate clutch (110) is completely disengaged.

[0214] When the operating pedal (140) is positioned in the first position, the power transmission rate through the multi-plate clutch (110) becomes 0%.

[0215] When the operating pedal (140) is positioned in the second position, the multi-plate clutch (110) is fully engaged.

[0216]

[0217] When the operating pedal (140) is positioned in the second position, the power transmission rate through the multi-plate clutch (110) is 100% and the fastening strength of the multi-plate clutch (110) is maximized.

[0218] Referring to Fig. 4, the operating pedal (140) is maintained at the third position with a displacement rate of 50%.

[0219] Even when the displacement ratio of the operating pedal (140) is 50%, the power transmission ratio of the multi-plate clutch (110) becomes 100%. However, the pressure is maintained at a level lower than the maximum pressure for a predetermined period of time corresponding to the displacement ratio of the operating pedal (140) and then reaches the maximum value.

[0220] The transmission control method of the above work vehicle (100) is explained with reference to the flow chart of Fig. 5.

[0221] The present invention is characterized by the process in which the multi-plate clutch (110) switches from a power-cutting state to a power-transmitting state, and therefore this will be described.

[0222] 1. Check the operating status <s100>

[0223] The controller (130) checks whether the user has stepped on the operating pedal (140) with his / her foot and has moved to the release state by taking his / her foot off the operating pedal (140).

[0224] The controller (130) can check whether the operating pedal (140) is released using the detection information received from the displacement sensor (150).

[0225] According to the operation status check, it is confirmed whether the current state of the operation pedal (140) has been switched to a release state for power transmission or whether the restraint state for power cutoff is maintained.

[0226] 2. Proportional control valve control <s200>

[0227] When the operating state of the operating pedal (140) is confirmed to be released in step S100, the controller (130) controls the proportional control valve (121) so that power transmission is performed through the multi-plate clutch (110).

[0228] In the released state, the controller (130) controls the proportional control valve (121) so that the multi-plate clutch (110) is engaged.

[0229] In step S200, the controller (130) executes somewhat different control depending on whether the operating pedal (140) is operated abruptly, so step S200 will be examined in more detail.

[0230] 2-1. Determination of release status <s210>

[0231] The controller (130) determines whether the release of the operating pedal (140) was rapid or relatively slow.

[0232] 2-2. Control according to the first control section (CS1) <s220> <s240>

[0233] When the release of the operating pedal (140) is performed abruptly, the controller (130) performs control such as the first control section (CS1) illustrated in the graph of FIG. 2. <s220>.

[0234] When the release of the operating pedal (140) is slow, the controller (130) performs control such as the first control section (CS1) illustrated in the graph of FIG. 3. <s240>.

[0235] In the first control section (CS1), the controller (130) controls the proportional control valve (121) so that the pressure increases at an average rate of change smaller than the rate of change in displacement of the operating pedal (140).

[0236] In both the example of Fig. 2 and the example of Fig. 3, the control according to the first control section (CS1) is the control according to the contact point entry section (ES). <s221> <s241>Control according to the transmission rate increase section (GS) <s222> <s242>It is divided into .

[0237] The rate of change of the pressure in the contact point entry section (ES) and the rate of change of the pressure in the transmission rate increase section (GS) are different.

[0238] The controller (130) controls the proportional control valve (121) so that the rate of change of the applied pressure is different in the contact point entry section (ES) and the transmission rate increase section (GS).

[0239] In the control according to the contact point entry section (ES), the controller (130) controls the proportional control valve (121) to discontinuously and stepwise increase the hydraulic pressure applied to the multi-plate clutch (110). Accordingly, the pressure also changes while discontinuously and stepwise increasing.

[0240] When the pressure in the contact point entry section (ES) reaches the contact start point, the contact point entry section (ES) ends and the transmission rate increase section (GS) begins.

[0241] In the transmission rate increase section (GS), the controller (130) controls the proportional control valve (121) so that the power transmission rate through the multi-plate clutch (121) becomes 100% while the pressure is maintained within a certain range.

[0242] The rate of change of the pressing force in the transmission rate increasing section (GS) is smaller than the rate of change of the pressing force in the contact point entry section (ES).

[0243] The average rate of change in the pressure in the transmission rate increasing section (GS) is smaller than the average rate of change in the pressure in the contact point entry section (ES).

[0244] 2-3. Control according to the second control section (CS2) <s230> <s250>

[0245] Control according to the second control section (CS2) begins after control according to the first control section (CS1) ends.

[0246] The second control section (CS2) starts at the point where the first control section (CS1) ends.

[0247] The second control section (CS2) starts at the point where the transmission rate increase section (GS) ends.

[0248] The second control section (CS2) starts when the power transmission rate through the multi-plate clutch (110) reaches 100%.

[0249] The controller (130) controls the proportional control valve (121) so that the rate of change in the pressure in the second control section (CS2) is greater than the rate of change in the pressure in the first control section (CS1).

[0250] The controller (130) controls the proportional control valve (121) differently depending on whether it is a rapid operation state or a normal operation state.

[0251] In case of a rapid operation state, the controller (130) controls the proportional control valve (121) so that the pressure reaches the maximum in the second control section (CS2). <s230>.

[0252] In the case of a normal operating state, the controller (130) controls each case separately in the second control section (CS2). <s250>

[0253] When the user gradually removes his / her foot from the operating pedal (140) and eventually removes it completely, the controller (130) controls the proportional control valve (121) so that the pressure reaches its maximum while adjusting the rate of change in the pressure according to the matching table. <s251>.

[0254] When the user slowly removes his / her foot from the operating pedal (140) so that the operating pedal (140) is maintained at the third position rather than the second position, which is the highest value, the controller (130) controls the proportional control valve (121) so that the pressure at the third position is maintained according to the matching table, as shown in FIG. 4.

[0255] When the operating pedal (140) is maintained in the third position, the power transmission ratio reaches 100%, but the pressing force is maintained lower than the maximum pressing force for a certain period of time.

[0256] After a certain amount of time, the pressure increases to its maximum value.

[0257] For a given period of time, a pressure corresponding to the third position of the operating pedal (140) is applied to the discs of the multi-plate clutch (110).

[0258] <Second Embodiment>

[0259] FIG. 6 is a schematic diagram for explaining the main components of an agricultural work vehicle (100, hereinafter referred to as “work vehicle”) according to a second embodiment of the present invention.

[0260] The work vehicle (100) of Fig. 6 includes a multi-plate clutch (110), an operator (120), a controller (130), an operator pedal (140), a displacement sensor (150), and an acceleration sensor (160).

[0261] The multi-plate clutch (110), actuator (120), actuator pedal (140), and displacement sensor (150) function in the same manner as in the first embodiment.

[0262] The acceleration sensor (160) detects the acceleration of the work vehicle (100).

[0263] In the present invention, information detected from the acceleration sensor (160) is utilized when the user takes his / her foot off the operating pedal (140).

[0264] Figure 7 shows two examples with different time lengths of the contact point entry segment (ES).

[0265] In Fig. 7 (a), the time length of the contact point entry section (ES) is short, and in Fig. 7 (b), the time length of the contact point entry section (ES) is long.

[0266] When the time length of the contact point entry section (ES) is short, a large impact occurs, and when the time length of the contact point entry section (ES) is relatively long, a small impact occurs.

[0267] The magnitude of the instantaneous shock represents the instantaneous change in acceleration.

[0268] If the instantaneous change in acceleration is large, the impact is large, and if the instantaneous change in acceleration is small, the impact is small.

[0269] The controller (130) analyzes the instantaneous acceleration change amount from the acceleration information from the acceleration sensor (160) and then controls to increase or decrease the time length of the subsequent contact point entry section (ES).

[0270] The controller (130) can adjust the time required for the contact point entry section (ES) according to the set appropriate relationship between the amount of impact and the shifting time.

[0271] The controller (130) can control the time required for the contact point entry section (ES) based on acceleration information received from the acceleration sensor (160) so that the amount of shock generated during the gear shifting process is at an appropriate level.

[0272] <Third Embodiment>

[0273] Figure 8 is a graph for explaining a third embodiment of the present invention.

[0274] In the third embodiment, the initial starting pressure at the contact point entry section (ES) can be arbitrarily set by the user (administrator).

[0275] The initial starting pressure is greater in (b) of Fig. 8 than in (a) of Fig. 8 (p1 < p2), and the initial starting pressure is greater in (c) of Fig. 7 than in (b) of Fig. 7 (p2 < p3).

[0276] As the contact start point (SP) is reached more quickly from (a) of Fig. 8 to (c) of Fig. 8, the reaction of the multi-plate clutch (110) as the manager operates the operating pedal (140) becomes faster.

[0277] The manager may also omit the contact point entry section (ES) by setting the initial starting pressure (p4) to reach the contact start point (SP) as in (d) of Fig. 8.

[0278] When the third embodiment is applied, an appropriate relationship between the degree of shock generated during the engagement process of the multi-plate clutch (110) and the time for gear shifting to be completed can be arbitrarily set based on the experience of users, etc.

[0279] As shown in Fig. 9, in order for the third embodiment to be applied, the work vehicle needs to have a setting means (170).

[0280] Administrators, such as users, arbitrarily set the initial starting pressure by manipulating the setting means (170).

[0281] The above-described embodiments are merely preferred examples, and the present invention may have various applications or modifications. Therefore, the present invention should not be construed as being limited to the above-described embodiments. Instead, the scope of the present invention should be construed in accordance with the separately stated claims and their equivalents. < / s230> < / s222> < / s221> < / s220>

Claims

1. Operation status confirmation step for checking the operation status of the operation pedal (140) for operating the multi-plate clutch (110). <s100> ;< / s100> The above operation status confirmation step <s100>When the operating state of transmitting power is confirmed, a proportional control valve control step for controlling the proportional control valve (121) so that the multi-plate clutch (110) is engaged <s200>; including, The above proportional control valve control step <s200> It includes a first control section (CS1) and a second control section (CS2) in which the rate of change of the pressure (hereinafter referred to as “pressure”) applied to the disks of the multi-plate clutch (111) is different. The above second control section (CS2) starts at the point where the above first control section (CS1) ends, In the above first control section (CS1), the proportional control valve (121) is controlled so that the pressure increases with an average change rate smaller than the displacement change rate of the operating pedal (140). In the second control section (CS2), the proportional control valve (121) is controlled so that the rate of change in the pressure is greater than that in the first control section (CS1). A transmission control method in an agricultural work vehicle (100).

2. In paragraph 1, The above first control section (CS1) is divided into a contact point entry section (ES) and a transmission rate increase section (GS). In the above contact point entry section (ES), the pressure enters the point where contact begins between the disks of the multi-plate clutch (110) (SP, hereinafter referred to as the 'contact start point'). In the above transmission rate increase section (GS), the power transmission rate increases from the point where the contact point entry section (ES) ends. The proportional control valve (121) is controlled so that the rate of change of the pressure is different in the above contact point entry section (ES) and the above transmission rate increase section (GS). A transmission control method in an agricultural work vehicle (100).

3. In paragraph 2, The proportional control valve (121) is controlled so that the rate of change of the pressure in the above transmission rate increase section (GS) is less than the rate of change of the pressure in the contact point entry section (ES). A transmission control method in an agricultural work vehicle (100).

4. In paragraph 2, Control the proportional control valve (121) so that the pressure increases discontinuously at the above contact point entry section (ES). A transmission control method in an agricultural work vehicle (100).

5. In paragraph 2, The proportional control valve (121) is controlled so that the pressure in the above contact point entry section (ES) increases stepwise in a step-like manner. A transmission control method in an agricultural work vehicle (100).

6. In paragraph 2, In the above transmission rate increase section (GS), the proportional control valve (121) is controlled so that the power transmission rate by the multi-plate clutch (110) reaches 100%. In the second control section (CS2), the proportional control valve (121) is controlled so that the pressure reaches the maximum. A transmission control method in an agricultural work vehicle (100).

7. In paragraph 2, The initial starting pressure can be arbitrarily set at the above contact point entry section (ES). A transmission control method in an agricultural work vehicle (100).

8. In paragraph 2, The time required for the contact point entry section (ES) is adjusted based on the acceleration information received from the acceleration sensor (160). A transmission control method in an agricultural work vehicle (100).

9. In paragraph 2, The above operation status confirmation step <s100> If the operation state confirmed in is not the maximum value, the proportional control valve (121) is controlled in the second control section (CS2) to maintain the pressure lower than the maximum pressure for a predetermined period of time. A transmission control method in an agricultural work vehicle (100).

10. Operation status confirmation step to check the operation status of the operation pedal (140) for operating the multi-plate clutch (110). <s100> ;< / s100> The above operation status confirmation step <s100>When the operating state of transmitting power is confirmed, a proportional valve control step for controlling the proportional control valve (121) so that the multi-plate clutch (110) is engaged <s200> ; including, The above proportional valve control step <s200> The proportional control valve (121) is controlled so that a pressure less than the maximum pressure is applied to the discs of the multi-plate clutch (110) from the point where power starts to be transmitted to the point where the power transmission rate becomes 100%. A transmission control method in an agricultural work vehicle (100).

11. In paragraph 10, The proportional control valve (121) is controlled so that the pressure applied to the disks is maintained within a predetermined range from the point where the power transmission starts to the point where the power transmission reaches 100%. A transmission control method in an agricultural work vehicle (100).

12. A multi-plate clutch (110) capable of transmitting or blocking power transmission; A proportional control valve (121) that operates the multi-plate clutch (110) to enable the multi-plate clutch (110) to transmit or block power; A controller (130) capable of controlling the operating state of the multi-plate clutch (110) by controlling the proportional control valve (121); An operating pedal (140) for inputting a user's command to the above controller (130); and It includes a displacement sensor (150) that detects the displacement of the above operating pedal (140); The above controller (130) executes gear shifting according to one of the gear shifting control methods of claims 1 to 11 based on the detection information from the displacement sensor (150). Agricultural work vehicles (100).

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